Re: 12 LED resistance circuit help


"John Fields" <jfields@xxxxxxxxxxxxxxxxxxxxx> wrote in message
news:hcqs61t28efpnkqujvjk680fe75q6f7mm7@xxxxxxxxxx
> On Tue, 26 Apr 2005 01:46:16 GMT, "Anthony Fremont"
> <spam@xxxxxxxxxxxx> wrote:
>
>
> >The point had nothing to do with whether it worked or not. The point
> >was your mistake, or "trypo" as you like to call them.
>
> ---
> I think I already admitted that but, just in case you missed it, here
> ya go: I made a typographical error. Happy now?
> ---
>
> >
> >> ---
> >>
> >> >Just like the fact that it wouldn't have worked anyway.
> >>
> >> ---
> >> You say that now like you knew it then, but the _fact_ is had Fred
not
> >> found it you'd still be just as in the dark now as you were then.
> >
> >I never bothered to look that close. Obviously Fred is well aware
that
> >you often post non-working circuits.
>
> ---
> Well, since this _is_ an electronics group, I post circuits. Some
> have technical errors in them, some don't. They usually get fixed.
> The point is, _I_ post circuits. You, OTOH, critique typos when
> someone catches you in a technical error.
> ---
>
> >It might be different if I was actually looking for errors in the
> >schematic, but I simply wasn't. I just noticed the glaring "trypo"
in
> >the text.
>
> ---
> More's the pity.
> ---
>
>
> >> >LMAO I'm not the one
> >> >touting myself as a "professional circuit designer".
>
> ---
> Perhaps that's because you aren't.

Well duh, that would be the appropriate thing to do wouldn't it?

> It's what I do for a living, so that makes it my profession. So I put
> what I do in my .sig, what's wrong with that?
>
> Interestingly, the fact that I do seems to thoroughly irk you since
> you've mentioned it in a derogatory way more than once. Perhaps it's
> because I choose to include "Professional" and you think that I should
> be more humble and merely post "Circuit designer"? Perhaps you need
> to get over yourself and come to the realization that not everyone is
> going to accede to your whims as to what does and what doesn't
> constitute proper behavior.

Did I say that somewhere? Since you mentioned it, don't you find the
word professional to be tiny bit redundant? Why do you feel a need to
tell the world that you really do get paid?

> >Do you think that I have no other skills, or is circuit design all
that
> >is important?
>
> ---
> What skills you may have, other than in electronics, are of very
> little interest to me since, in these groups, what's important is

Translation: Yes, you probably do know a bunch of stuff that I don't
know, but since I don't know it, it's not relevant.

> electronics and the ability to communicate. In seb, it's also

Have I not communicated well enough?

> important to be able to render technical criticism
> non-confrontationally in order to not scare off the newbies.

Have you _ever_ seen me be confrontational to a newbie?

> ---
>
> >> >I'm in it for the hobby and I've never pretended any different.
> >>
> >> ---
> >> Good move on your part since the pretense would easily be found
out.
> >
> >Kinda like the pretense where you come off as a civil human being?
>
> ---
> I generally respond to civility with civility and to non-civility with
> non-civility, and I very seldom make a non-preemptive strike.

You probably meant preemptive (without the non).

> ---
>
> >> >Perhaps you should have
> >> >told the OP that your circuit was untested and unsimulated,
because
> >even
> >> >I made the mistake of figuring that you actually posted stuff that
> >you
> >> >knew would work.
> >>
> >> ---
> >> "Even" you? My, my, you _are_ a pretentious little prick, arent
you?
> >
> >Actually, I meant that in a gullable sort of way. I've got your
number
> >now though.
>
> ---
> Did you know that 'gullable' isn't in the dictionary?

Oh man, you're not going to start tossing spelling flames are you? How
lame.

> ---
>
> >> You, on the other hand, seem to be interested in little more than
> >> assuaging the effects that "current hogging" incident had your ego.
> >
> >Actually, I've been getting a kick out of watching you blow your top.
> >:-)
>
> ---
> Just a ruse to get you to bite, and now that the hook is set I own
> you!

ROTFLMAO, oh yeah I'm definitely hooked.

> ---
>
>
> >I seriously doubt that I'll be reporting back much of anything about
any
> >of your circuits.
>
> ---
> As do I. After all, it takes a modicum of acumen to do much more than
> discover a typo in a technical article.

Modicum and acumen in the same sentence. No wonder it took you all
night to respond.

> ---
>
> >I do suspect that I will be hearing from you more often in the future
though.
>
> ---
> Perhaps.
>
> I will say one thing now, though, and that is that after having
> checked your posting history last night I found that you do seem to
> know what you're talking about, technically, most of the time, so I
> apologize for any inaccurate broad-brush slurs I may have made
> earlier.
>
> However, as far as the PIC VS "discrete" logic thing goes, you're
> still all wet. :-)
> ---

OMG, I can't believe it. That must have been really hard. Maybe we can
coexist then.


> >> Well, duhhh...
> >>
> >> If you can't write properly, how can you expect people not to
> >> misunderstand you?
> >
> >My comments in the original post were rhetorical, haven't you figured
> >that out yet?
>
> ---
> Nope. Would you mind going back and dredging up those comments and
> explaining what made them rhetorical?

OK, here we go:

First I said, "Maybe I could help make amends by belittling others,
nit-picking posts and posting a bunch
of OT crap?". Then I said, "Lets see if we can't get on to the road to
recovery now." That's all kinda the setup up indicating that sarcastic
and rhetorical remarks may follow. And then they did. I jibed Watson
since he tossed the first punch and you for what amounts to several
reasons (mainly your setup question when I've never slapped at you
before, I knew what you were trying to do and it torqued me off,
finally I've frankly found you to be a bit offensive lately and without
cause to other people namely Larry). So while it may not have been
entirely rhetorical, I really didn't expect this outcome.



> ---
>
>
> >> ---
> >> So, when you can't defend yourself technically you slip into
sarcasm?
> >
> >What's to defend, I admitted my little faux pa.
>
> ---
> Then what was the reason for the sarcasm? Surely you realized it
> would lead to no good.


> ---
>
>
> >> >At any rate, you are the one setting the precident around here of
> ^^^^^^^^^
> precedent
>
> >> >jumping down someones throat when you don't like the accuracy of
> ^^^^^^^^
> someone's
> >their posts.

Why are spell checking my old posts now?

> >> ---
> >> If you want to find out how really stupid that statement is I
suggest
> >> you go to Google groups and read through my last 10,000 posts then,
> >> once you're done, report back here with what you've learned.
> >
> >I didn't have to read 10,000 of them to figure out that you often go
off
> >like this. Four letter words, invectives and ad-hominem attacks seem
to
> >be a part of your regular forte.
>
> ---
> Ahhh, you only read the juicy stuff. Try the tech, you might enjoy
> it.

I've read some of it and you have your good side.

> ---
>
>
> >> ---
> >> That's because you had nothing to do any "cussing out" about and
> >> because you're a ***.
> >
> >Really? Do ya think so?
>
> ---
> Wellll... yeah.
>
> After all, you say "WTF" so you can pretend that that's not saying
> "What The ***", which is a *** trait because pussies dont like the
> "F" word, and you say that you don't use "cuss words" when the

Actually I use the "F" word plenty well, I just tend to not spell it out
in usenet articles. Just trying to consider the children. ;-)

> acronym embodies the 'cuss words' you know the reader will expand
> mentally to yield the 'cuss words' you want to wield, but can't.
> So, your saying that you don't use 'cuss words' is a lie and lying is
> another *** trait.

Interesting extrapolation you made there.

> ---
>
>
> >> If you can't see that as making a scene, then saying that you
didn't
> >> feel the need to, then you're even stupider than I thought.
> >
> >As I said before, I didn't see a need to make a scene when I first
saw
> >your mistake in SED. After that, when you posted your little trick
> >setup question in SEB, I felt a bit different. And then after
Watson's
> >snide little remark about attrocious advice, I posted my little
> ^^^^^^^^^^
> atrocious
> >sarcastic rant. And now here we are. Is that timeline really so
hard
> >to grasp?
>
> ---
> Certainly not, but it's not about a timeline, it's about changing
> streams in mid-horse. What you said earlier, unconditionally, was that
> you didn't feel it was necessary to make a scene, while what you're

At the time that is how I felt. And then you changed all that when you
tried to bust my chops on current vs. power or "current hogging" as you
like to call it. So, you prompted the horse change, not me.

> saying now is that you're now attaching conditions which made it OK to
> make a scene. Can't you see that that's an ex post facto violation of
> the first statement by the second?
>
> "Please, Mommy, Oh, pleeeease make him give me back my marbles...
> ---
>
>
> >> So, you admit your reply was confrontational, and yet you said that
> >> you didn't feel a need to make a scene. You just can't keep your
> >> facts straight, can you?
> >
> >See above.
>
> ---
> See reply, above, to "See above"
> ---
>
>
>
> >> And, in view of the fact that you've proven yourself to be a liar,
and
> >> a stupid one at that, I maintain that you actually meant 'current
> >> hogging' and decided that 'power hogging' would be a nice little
> >> phrase to switch to to get you out of a jam.
> >
> >As I originally posted in reply to your little trick query:
> >
> ><quote>
> >Perhaps "dissipate more power" would have been more appropriate than
> >"hog more current".
> ></quote>
> >
> >So as we can all plainly see, 'current hogging' is your own little
> >fabrication of terminology that I never used.
>
> ---
> Not at all, just a substitution used to tighten up of the sloppy
> construct, which included my substitution of 'power hogging' for your
> "dissipate more power".

Yes, it's all about what serves your agenda best, isn't it?

> ---
>
> >> ---
> >> Yup, I thought so. You're the stereotypical petulant little puke
who,
> >> when she starts running out of ammunition starts whining about how
I
> >> should run _my_ business and how I should run _my_ life.
> >
> >If you think I'm running low on ammo, just keep posting. ;-) I
could
> >care less how you run your business _or_ your life. That is until
you
> >wish to horn into my life with your petulent, pedantic crap.
> ^^^^^^^^ ^
> petulant cuss word
>
> ---
> I don't consider B-Bs much of a threat, but I _am_ tiring of your
> uninspired banter, so unless you can pick up the pace I'm outta here.
> ---
>
>
> >> You were plain enough, the bobbing and weaving part was about the
> >> transfer to the "power hogging" ploy, the intent of which was to
make
> >> it seem like you knew what you were talking about, but merely used
the
> >> wrong choice of words to describe what you meant. What I'm saying
is
> >
> >Do you think that you've somehow proved that I didn't know the
> >difference?
>
> ---
> No. _You_ proved it with:
>
> "Since there are two LEDs in series, one may hog more current than the
> other resulting in its demise."
>
> I merely asked a question designed to determine whether you did, in
> fact, know the difference, but you took affrontery and refused to
> answer it directly.

And I thought by saying "dissipate more power" that I made it perfectly
clear that I knew what you were hinting at. How direct does something
need to be before you can see it?

> ---
>
> >> that I think you were being intellectually dishonest in that there
is
> >> no use of "power hogging" in the context into which you cast it.
> >> "Power hogging, in all the cases I've been able to find refers to
one
> >> device, alone or in parallel with others connected to a common
power
> >> supply, which draws what seems to be an inordinate amount of power
> >> from the supply.
> >
> >Again, like as stated earlier. I was originally going to say "juice"
> >not current and not power. Again, I wish that I had just so I could
see
> >how you could have twisted that around.
>
> ---
> Perhaps that's what you should have done. "Juice" is vague enough to
> have covered all your bases and is a cutesy colloquialism, so I
> probably would have just ignored it.

See, I knew I should have used it.

> ---
>
> >Is juice power, or is it current or maybe even energy?
> >Again, my original intent was not to use the word power either,
> >even though it would have been the "most correct" term.
> >Hard to believe that set you onto a personal crusade to prove me
> >a liar.
>
> ---
> You've supplied the proof, I merely pointed out the incidents.
> ---
>
>
> >> Again, the context of your "prompt" was goading and your attitude
was
> >> clearly confrontational, yielding a richly deserved insulting
reply.
> >
> >What type of reply do you think you deserve at this point in our
> >relationship?
> >
>
> >> >I think I can still tell the difference between current, power and
> >> >energy.
> >>
> >> ---
> >> Really? Then be my guest and tell us all about it...
> >
> >Why do I think that no matter what I posted you would ridicule it?
>
> ---
> That's not ridicule. I really don't think you know the difference and
> I'm challenging you to provide proof that you do.

Do you really think that? I doubt that you do.

In my own simple minded terms, current is the rate of electron flow. X
electrons in Y amount of time. Power is just putting some voltage
behind it so that we have the rate that work is being done, energy is
just putting a time constraint on how much total power is available to
do work (i.e. a 12V 8AH battery contains 96WH of energy). Is that good
enough or do you want joules, coulombs and other textbook what not?


> ---
>
> >> I can't imagine what makes you think you're important enough that I
> >> should give a *** about your past errors.
> >
> >As you have so aptly demonstrated, you would leave no stone unturned
in
> >order to crucify me.
>
> ---
> Oh, Gawd... Now you're casting yourself in the role of Christ and I'm
> pounding in the nails. Get over yourself.

If that's how you feel, maybe you should listen to your conscience.

> ---
>
> >> I know nothing about you which precedes your "current hogging" faux
> >> pas, and I'm _certainly_ not interested in the genealogy of the
huge
> >> family of errors I'm sure you've procreated over the years.
> >
> >Too funny.
>
> ---
> Thanks. :-)
> ---
>
>
> >> ---
> >> Awww... poor baby's playing the passive-aggressive "If you're
smarter
> >> than me then why pick on me?" card.
> >
> >I never said that I thought you were smarter than me. Only that you
> >knew more about electronics. Don't flatter yourself, there is a
> >difference.
>
> ---
> Not so far.

;-)

> ---
>
> >> I don't feel a need to dominate the NG, sweetie, but what I do like
to
> >> do is bring down self-important little bull*** artists like you,
just
> >
> >Self important bull*** artist? That's got to be the most serious
case
> >of projection I've ever seen. Do you see me waving my credentials
> >around? Do I have a sig line making bodacious claims?
>
> ---
> Nope, but then, you've got nothing to make bodacious claims about.

See, there you go making prejudicial statements again. You have no
idea.


> ---
>
> >> for fun. And as far as being an expert goes, I could be a complete
> >> moron and you'd still have to consider me an expert.
> >
> >That's not far from how I see things right now.
>
> ---
> Ah, a double entendre; how delicious! Intended?
> ---
>
> >> BTW, what happened with running those numbers to see whether the
power
> >> dissipation spec of an LED with Vf max in series with an LED with
Vf
> >> min and If running through _both_ of them would be exceeded?
> >
> >I don't know, what happened? How about you pick your own
experiments,
> >and I'll pick mine.
>
> ---
> Awww... baby demurs. And here I thought I was going to get to see
> some good stuff.
>
> OK, _I'll_ do it.
>
> Here's the circuit:
>
>
> E1
> |
> [R1]
> |
> +---->E2
> |
> [DS1]
> |
> +---->E3
> |
> [DS2]
> |
> GND
>
> Unfortunately, the data *** at the link you provided:
>
> http://www.epitex.com/Catalog_PDF/08_Point_source_LED/L590CE-34F.PDF
>
> doesn't show Vf min, and I couldn't find any Vf min for white LEDs so,
> since you said that Vf can vary 2:1, looking at a Vf max of 4.0V for a
> "typical" white LED at 20mA yields a Vf min of 2.0V. Also, 100mW
> seems to be a pretty typical max dissipation, so if we redraw the
> circuit with that in mind, and with LEDs with equal low Vf's we'll
> get:
>
>
> 9.0V-+---->E1
> |
> [R1]
> |
> 4.0V-+---->E2
> |
> [DS1]
> |
> 2.0V-+---->E3
> |
> [DS2]
> |
> GND
>
>
> The choice of 9V for E1 is based on the assumption that E1 will be
> regulated and will give 1V of headroom if DS1 and DS2 are both at Vf
> max.
>
> Now, since the current in a series circuit is everywhere the same,
> solving for R1 with 20mA of LED current yields:
>
> (E1-E2) 5V
> R1 = --------- = ------- = 250 ohms
> It 0.02A
>
>
> and the LEDs will each be dissipating:
>
>
> P = IE = 0.02A * 2V = 0.04W
>
>
> so everything will be fine.
>
>
> Now, though, let's select a high Vf LED for DS1 and see what happens.
>
>
> Here's the circuit now:
>
> 9.0V-+---->E1
> |
> [250]
> |
> 6.0V-+---->E2
> |
> [DS1]
> |
> 2.0V-+---->E3
> |
> [DS2]
> |
> GND
>
>
> Since we now have a 3V drop across R1 the current will fall to:
>
>
> E 3V
> I = --- = ------ = 0.012A
> R 250R
>
>
> and the power being dissipated by DS1 will be:
>
>
> P = 0.012A * 4V = 0.048W
>
> So, if the LED is rated for 100mW max, it will be dissipating 48mW
> and everything will still be fine, except the light output will
> suffer.
>
> If we have two Vf max LEDs in the circuit it'll look like this:
>
>
> 9.0V-+---->E1
> |
> [250]
> |
> 8.0V-+---->E2
> |
> [DS1]
> |
> 4.0V-+---->E3
> |
> [DS2]
> |
> GND
>
>
> and the current in the circuit will fall to:
>
> 1V
> I = ------ = 0.004A
> 250R
>
> So, while everything will still be fine from a power dissipation
> viewpoint, the light output from the LEDs will be greatly degraded.
>
> Although it would be possible to fiddle with supply voltages and
> series resistances in order to come up with a solution which would
> allow a greater light output without overdriving the LEDs regardless
> of the Vf spread, It would be more practical, IMO, to drive them with
> a constant current.

So there we have it, the OP has been proven wrong. His LED's could not
have possibly failed.

> ---
>
>
> >> If you'd pull that narcissistic little head out of your ass you
might
> >> come to the realization that you're not the arbiter of who's
deserving
> >> of what, and you might find that I am, in fact, civil. That
doesn't
> >
> >Really, and I'm supposed to be convinced by that statement? ROTFL
I
> >think I'll continue to decide for myself who I respect.
>
> ---
> Spoken like a true narcissist. It's 'whom', BTW.

I was honestly going to say that, but I didn't want to seem pretentious.
LOL

> ---
>
> >> mean that when a disingenuous little twat like you wanders in here
and
> >> starts playing games that she's not going to be called on it.
> >
> >Yeah, you're real civil.
>
> ---
> We've already covered that.

Yes, I'd agree that we buried your civility a good while ago.

.

Loading